Correct! I was rearranging the gfx cards in various computers last night in preparation to a processing challenge I'm taking part in next week. There's always odd compatibility issues and I also had to consider power requirements but I finally found a workable combination...

A bit abstract, but it's actually condensation inside the 100-400L. Again. I was using it in the rain today, preferring to risk it to get the extra reach over the 70-300L. Drying out nicely now. The 5D2 also got a soaking and it never left the bag! I shouldn't have used the outer pocket of my camera bag to hold my foldable umbrella, as water from it just soaked right through.